There is a plurality of medical conditions for which it is desired to occlude a body vessel, be it temporarily or permanently. Occlusion devices for this purpose could be categorized into two different types, a first which provides instant occlusion of a vessel and a second which relies on embolization. Instant occluders provide a physical barrier spanning across the diameter of the vessel and can achieve near instantaneous occlusion. Such devices, however, must remain reliably in place without migration or leakage through the occluder, between the occluder and the vessel wall. Embolization occluders provide a device which has at least one clotting promoter, such as a coil possibly with thrombogenic fibres attached thereto, and rely on the formation of a thrombus in the vessel to achieve occlusion. While these latter occluders take time to achieve occlusion, they tend to have high reliability once successfully deployed. In the case of embolization coils, it is often necessary to implant a series of coils in order to achieve the required degree of occlusion.
Examples of prior art occlusion devices can be found in U.S.-2005/0,065,547, U.S. Pat. No. 4,643,184, U.S. Pat. No. 4,832,055, U.S. Pat. No. 5,108,420, U.S. Pat. No. 5,456,693, U.S. Pat. No. 6,143,015, U.S.-2002/0,065,545, U.S.-2002/0,198,563, U.S.-2005/0,065,546, U.S.-2005/0,165,441, U.S.-2005/0,228,434, U.S.-2006/0,074,484, U.S.-2010/0,114,299, U.S.-2011/0,282,274, U.S.-2013/0,096,550 and WO-2007/110,195.